Process and apparatus for making calcium acetate and by-products.



J. GENDREAU.

PROCESS AND APPARATUS FOR MAKING CALCIUM ACETATE AND BY-PRODUCTS.

APPLICATION FILED MAY 3, 1918.

1 &3 Patented Aug. 20, 1918.

WEnd .fll'filllat'a 7 l 76 C'qnzierzder If I r 22 v JACQUES GENDREAU, OF SHANGHAI, CHINA.

Specification of Letters Patent.

Patented Aug. 20, 1918.

' Application filed May 3, 1918. Serial No. 232,336.

To all whom it may concern:

Be it known that I, JACQUES GENDREAU, a citizen of the French Rephblic, residing at Shanghai, China, have invented certain new and useful Improvements in Processes and Apparatus for Making Calcium Acetate and By-Products; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of the present invention is to provide an economical and efiicient process and apparatus for continuously producing calcium acetate from liquors containing acetic acid, particularly wood distillate, with the complete recovery of the by-products in a relatively pure condition, suitable for use in the arts.

An apparatus for use in carrying outthe process is illustrated in the accompanying drawings, in which Figure 1 shows a vertical section of an apparatus within the scope of my invention, and Fig. 2 shows a sectional plan view thereof taken on the line 22 of Referring to said drawings, the numeral 10 represents an inclined sole plate forming the bottom of the vaporizing chamber. This plate is chambered as shown at 11,a tortu' ous passage being thereby provided, extending the entire length of the sole plate, and the upper surface of this plate is composed of a large number of steps, each comprising a slightly inclined tread and a. riser. The passages 11 are connected with a supply pipe 12 for the introduction of superheated steam or other appropriate heating fluid, and an outlet pipe 13 at the lower end of the sole plate connects with a trap 14, for withdrawing the condensate produced in the said passage 11. The end wall 15 forms the end both of the vaporizing chamber and of the absorbing chamber to be described farther on. At the lower end of the sole plate is placed a receptacle 16 for collecting the unvaporized liquid, which when treating wood distillate, may consist entirely or partially of tarry matter. This liquid is suitably withdrawn through the tank 1'. to any suit able outlet. The tar pot 17 may also act as a cooler.

Forming the upper boundary of the vaporizing chamber is a plate 18 provided with numerous spaced upwardly extending bafiies 19, and above the plate 18 is placed a plate 20 provided with numerous downwardly extending baflles 21. The liquid to be distilled, for example, Wood distillate, is introduced into the vaporizing chamber through the valve pipe 22, and an absorbent liquid such as milk of lime is introduced into the absorbing chamber through the valved pipe 23.

The operation of the apparatus is as follows: Wood distillate is fed from tank 2-1 through valved pipe 22 on to the upper surface of the plate 10, and this liquid then streams down over the successive steps of the plate, during which operation superheated steam or other heating fluid is introduced through pipe 12 into the tortuous passage 11, and the water of condensation drawn off through pipe 13 into trap 14. During this operation the methyl alcohol and the acetic acid content, together with other readily volatile constituents of the wood distillate, are vaporized. This vapor thereby produced comes into contact with the under surface of the plate 18 and acts as a heating medium for the liquid in the absorbing chamber. The vapor passes upwardly through the passage 25 into the space 26, and thence into and upwardly through the absorption chamber formed by the plates 18 and 20. The upwardly extending baiiles 19 and the downwardly extending baffles 21 are of such sizes relatively to each other and to the dimensions of the absorption chamber, that the vapor is forced to bubble through the absorbent liquid in the several compartments of the absorption chamber. To this end an absorbent liquid such as milk of lime from tank 22 is fed in regulated quantity through the valved pipe 23 into the upper end of the absorption chamber, and this liquid overflows the successive bailies 19, and in each of the compartments of the absorp tion chamber, the vapors from the vaporizer coming through pipe 25, space 26 are caused to bubble through the said absorbing liquor.

In thus being caused to bubble through the liquor, two particular actions are produced. First the acetic acid vapor is absorbed by the milk of lime, producing calcium acetate, which remains in solution. The heat of the vapor coming into intimate contact with the liquid maintains the liquid at a high temperature, whereby any methyl alcohol wlnch may have been absorbed in said liquid is at once driven out, in the vapor form, and this vapor is swept along with the current of vapor passing upwardly through the absorbing apparatus. lhe liquid in the absorbing apparatus is moreover kept hot by means of the vapors in the vaporizing paratus, which are not then in contact with the absorbent liquid. The methyl alcohol vapor which is not taken up by the absorbent liquor, or which it taken up by the absorbent liquid is subsequently driven out by the heat of the vapors, is drawn oft through suitable pipe connection 28 to a condenser, wherein it is condensed to produce methyl alcohol. Any suitable form of condenser may be employed for this purpose.

The calcium acetate solution from the absorber in the lower part of the space 26 is strongly heated by the vapors of methyl alcohol acetic acid in the upper part of the tank 16, and being maintained in this manner at a temperature near the boiling point of acetic acid, the entire amount of methyl alcohol is driven out therefrom, immediately before said acetate solution is drawn off to tanl: 30. The liquor from 30 is drawn otl to any suitable evaporating apparatus or other device :tor using the ciuin acetate solution.

l t hat claim is:

l. A process which comprises continuously admitting wood distillate containing methyl alcohol, acetic acid and tarry mat ters less volatile than acetic acid, to the upper end of an inclined conduit, heating the said distillate by a heating fluid out of direct contact therewith, to an extent sufficient to induce volatilization of at least the major portions of the said alcohol and acid, causing the vapor produced to traverse a counter-flowing current of an alkaline absorbent liquid, which is maintained in a heated condi 'on, both by the vapors in corn tact therewith and undergoing absorption, and by the vapors in the vaporizing vessel which have not yet come into contact therewith, while causing said vapors undergoing absorption to be repeatedly bubbled through the said absorbent lionid, whereby the acid is very complete absorbed said vapors, erehy F n 8ft.)

may be absorbed thereby is effectively driven out again into the flowing vapor current, drawing off the alcohol vapor and condensing the same, and separately drawing oi the acetate solution and the tarry liquid, all in a continuous process substantially as and for the purposes hereinabove set forth.

2. In an apparatus for the distillation or wood distillate, the combination of a vaporizer provided with a stepped sole plate having heating-fluid spaces therein, and having its upper surface composed of a series of in clined steps, a valved pipe connection to said heating spaces, and an absorber overlying said vaporizer, with a vapor passage located at the lower ends of said elements, said ab sorber comprising in series, a plurality of compartments formed by upwardly extending baffles from the lower wall thereof and interspaced downwardly extending ba'lfies from the upper wall thereof, whereby the vapor passing upwardly therethrough is caused to bubble repeatedly through the liquid passing downwardly therethrough, and whereby heat is transferred from the vapors in the vaporizer into liquid in the ab sorber, means for introducing liquids at the upper end of both he vaporizer and the ab sorber, and for drawing 0d liquids separately from the lower ends of both the vaporizer and the absorber-and for drawing off vapor from the upper end of the absorber, substantially as described,

3. An inclined vaporizing vessel with an inclined absorbing vessel mounted thereupon, said absorbing vessel having means for repeatedly bringing the vapors therein into intimate contact with the liquid therein, a vapor connection between the lower end or" the vaporizing vessel and the lower end of the absorbing vessel, a liquid inlet to the upper end oi the vaporizing vessel, liquid outlets at the lower ends of both the vaporizvessel and the absorbing vessel. and a vapor outlet at the upper end of the absorbing vessel. p

testimony 'whereor, l ailin my signa- 

